1. Field of the Invention
The present invention relates to an optical fiber cutting device and optical fiber cutting method for smoothly cutting optical fibers
2. Description of the Related Art
Plastic optical fibers (referred to as xe2x80x9coptical fibersxe2x80x9d hereinbelow) are widely used for optical communication, opto-electric switching, etc. In these areas of usage, optical fibers are connected to other optical fibers and to optical receiving and emitting elements. In this situation, the end surface of the optical fiber must be smooth because the condition of the end surface of the optical fiber influences the transmission loss of the light.
Conventionally, in order to make the end surface of the optical fiber smooth, optical polishing and mirror surface transfer processing are carried out after cutting, as disclosed, for example, in Japanese Patent Application, Second Publication, No. Sho 62-57001 (1987). However, these operations have the drawback that their operability is low.
Thus, devices which omit this kind of end surface smooth processing and, obtain a sufficiently smooth end surface by cutting with the object of improving operability, are disclosed, for example, in Japanese Utility Model, Second Publication. No. Sho 62-15762 and Japanese Utility Model, First Publication, No. Hei 5-75703. The device disclosed in Japanese Utility Model, Second Publication, No. Sho 62-15762, is a cutting device provided with a pair of side walls having insertion holes for supporting the optical fiber and one cutting blade, and obtains a smooth end surface by precisely moving the cutting blade. In the device disclosed in Japanese Utility Model, First Publication. No. Hei 5-75703, a cutting blade with a fan shape set at 30-50xc2x0, thereby suppressing damage of the blade.
However, the device in Japanese Utility Model, Second Publication, No. Sho 62-15762 can make the end surface of the optical fiber sufficiently smooth, but it has the drawback that if the cutting blade is thin, the cutting blade will deteriorate easily. In addition, the device disclosed in Japanese Utility Model, First Publication, No. Hei 5-75703 has the drawback that half of the end surface of the optical fiber is in a cleaved state because the cutting weight rapidly decreases after the cutting blade transits the center of the optical fiber.
In addition, a small optical fiber cutting device which can obtain a smooth end surface is disclosed in Japanese Utility Model, First Publication, No. Hei 7-26802. In this cutting device, an optical fiber is clipped and cut by manually rotating on the center of a fulcrum at least one of an optical fiber anchoring member or a blade support member which supports the blade, and between the optical fiber anchoring member and the blade support member, an elastic body such as a spring is used. Because of this, the elastic strength of the elastic body increases as the cutting progresses, and as a result, the speed of the movement of the cutting blade decreases. In addition, the speed of the movement of the cutting blade can be adjusted so as to slow down after completing the cutting of half of the cross-section area of the optical fiber.
However, in this cutting device, the cutting speed depends on the size of the manual force applied at the time of cutting. Thus, the cutting speed is irregular, and stable cutting cannot be carried out. Also, there are the problems that the optical fiber may be cut at an inappropriate cutting speed. Because of the instability or inappropriateness of the cutting speed, the cut surface may be insufficiently smooth.
In summary, up to the present, an optical fiber cutting device and an optical fiber cutting method wherein the cutting blade deteriorates with difficulty and the smooth entire end surface of the optical fiber can be obtained and the optical fiber can be cut stably nave not been proposed.
The optical fiber cutting device of the present invention provides a speed reduction part which transmits drive force by reducing the drive speed of the external drive force, a drive force transmission part which transmits the drive force from the speed reduction part to the cutting blade holder, a cutting blade holder, a cutting blade which is held by the cutting blade holder and moves with the cutting blade holder to the cutting position, and an optical fiber supporter which holds the optical fiber so as to be perpendicular to the cutting blade at the cutting position.
In addition, if cutting blade having a blade thickness of xcex1 (mm) is used, and this cutting blade is moved at a speed of xcex2 (mm/minute), xcex1 and xcex2 are set so as to fulfill the following expression (1):
xcex2xe2x89xa6xe2x88x92253xcex1+65xe2x80x83xe2x80x83Exp. (1)
In addition, it is further preferable that said drive force be provided by a rotating motor, and that said speed reduction part be a set of speed reduction gears which reduces the rotation speed of the above motor, and further, that said drive force transmission part comprise a cam which rotates along with the rotation of said set of speed reduction gears and a cam follower which moves rectilinearly along with the rotation of said cam.